Space observatories are among some of the most magnificent buildings devoted entirely to science — because their windows look out on the universe. And their distinctive shape makes them into poignant ruins. Here are some observatories whose views onto space have been lost to time.

Cointe Observatory, Liège, Belgium, designed by Lambert Noppius and built in 1881-1882.

The Mohon del Trigo, built in 1902 in the Sierra Nevada, Andalucia, Spain. Abandoned since the 1970s.

Warner & Swasey Observatory in Cleveland, Ohio, constructed in 1919 by Worchester R. Warner and Ambrose Swasey. It had a 9.5-inch refractor after its opening, but later a 24-inch Burrell Schmidt and a 36-inch Cassegrain telesope were installed. Due to the growing light pollution in the city a new observatory was built and the complex was sold in 1983. It's abandoned since then.

The small Knightridge Space Observatory with a four-ton telescope, built in 1936 and 1937, Bloomington, Indiana

The castle-like Pip Ivan Observatory, on the top of a mountain named Pip Ivan in Ivano-Frankivsk, Ukraine. It was erected in 1937 and it was used for only a year by Polish astronomers. The Red Army captured the building in 1938 and used it as a meteorological station. The complex is abandoned since 1944.

The Felix Aguilar Observatory, Argentina.

The working and the abandoned Portage Lake Observatory, Dexter, Michigan, operated by the University of Michigan.

Innisfil Observatory, Innisfil, Ontario, Canada, built in 1975 by Heinz Lorenz, closed in the 1990s due to growing light pollution. The equipment was removed in 1997, and the building was converted to a house. Now it's abandoned.